Access to the PVR SPR is normally forbidden from userspace apps.  The
Linux kernel, however, fixes up reads in the appropriate trap handler.
To permit applications that read PVR to run on QEMU, then, we need to
implement the same handling of PVR reads.
Signed-off-by: NNathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Nmalc <av1474@comtv.ru>